Spring Boot中是否有Filter类(用于web应用程序)的注释?也许@Filter ?
我想在我的项目中添加一个自定义过滤器。
Spring Boot参考指南中提到过 FilterRegistrationBean,但我不确定如何使用它。
Spring Boot中是否有Filter类(用于web应用程序)的注释?也许@Filter ?
我想在我的项目中添加一个自定义过滤器。
Spring Boot参考指南中提到过 FilterRegistrationBean,但我不确定如何使用它。
当前回答
过滤器主要用于日志文件中。它根据您在项目中使用的记录器而有所不同。
让我解释一下log4j2:
<Filters>
<!-- It prevents an error -->
<ThresholdFilter level="error" onMatch="DENY" onMismatch="NEUTRAL"/>
<!-- It prevents debug -->
<ThresholdFilter level="debug" onMatch="DENY" onMismatch="NEUTRAL" />
<!-- It allows all levels except debug/trace -->
<ThresholdFilter level="info" onMatch="ACCEPT" onMismatch="DENY" />
</Filters>
过滤器用于限制数据,我使用阈值过滤器进一步限制流中的数据级别。我提到了可以限制的水平。
请参见“log4j2 - Log4J Levels”的级别顺序:ALL > TRACE > DEBUG > INFO > WARN > ERROR > FATAL > OFF
其他回答
我在这里看到了很多答案,但我没有尝试任何一个。我刚刚创建了如下代码所示的过滤器。
import org.springframework.context.annotation.Configuration;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
@WebFilter(urlPatterns = "/Admin")
@Configuration
public class AdminFilter implements Filter{
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("happened");
}
@Override
public void destroy() {
}
}
我让剩下的Spring Boot应用程序保持原样。
使用@WebFilter注释,可以这样做:
@WebFilter(urlPatterns = {"/*" })
public class AuthenticationFilter implements Filter{
private static Logger logger = Logger.getLogger(AuthenticationFilter.class);
@Override
public void destroy() {
// TODO Auto-generated method stub
}
@Override
public void doFilter(ServletRequest arg0, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
logger.info("checking client id in filter");
HttpServletRequest request = (HttpServletRequest) arg0;
String clientId = request.getHeader("clientId");
if (StringUtils.isNotEmpty(clientId)) {
chain.doFilter(request, response);
} else {
logger.error("client id missing.");
}
}
@Override
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
}
我看到Vasily Komarov的答案。这里有一个类似的方法,但是使用抽象的HandlerInterceptorAdapter类而不是使用HandlerInterceptor。
这里有一个例子……
@Component
public class CustomInterceptor extends HandlerInterceptorAdapter {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
}
}
@Configuration
public class InterceptorConfig extends WebMvcConfigurerAdapter {
@Autowired
private CustomInterceptor customInterceptor ;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(customInterceptor );
}
}
你也可以使用@WebFilter来创建一个过滤器。这样就行了。
@Configuration
public class AppInConfig
{
@Bean
@Order(1)
public FilterRegistrationBean aiFilterRegistration()
{
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new TrackingFilter());
registration.addUrlPatterns("/**");
registration.setOrder(1);
return registration;
}
@Bean(name = "TrackingFilter")
public Filter TrackingFilter()
{
return new TrackingFilter();
}
}
这是一个建议而不是答案,但如果你在你的web应用程序中使用Spring MVC,最好使用Spring HandlerInterceptor而不是Filter。
它可以做同样的工作,但是
可以使用ModelAndView吗 它的方法可以在请求处理之前和之后调用,或者在请求完成之后调用。 它很容易测试
1. 实现HandlerInterceptor接口,并向类中添加@Component注释
@Component
public class SecurityInterceptor implements HandlerInterceptor {
private static Logger log = LoggerFactory.getLogger(SecurityInterceptor.class);
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
request.getSession(true);
if(isLoggedIn(request))
return true;
response.getWriter().write("{\"loggedIn\":false}");
return false;
}
private boolean isLoggedIn(HttpServletRequest request) {
try {
UserSession userSession = (UserSession) request.getSession(true).getAttribute("userSession");
return userSession != null && userSession.isLoggedIn();
} catch(IllegalStateException ex) {
return false;
}
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {
}
}
2. 配置拦截器
@Configuration
public class WebConfig implements WebMvcConfigurer {
private HandlerInterceptor securityInterceptor;
@Autowired
public void setSecurityInterceptor(HandlerInterceptor securityInterceptor) {
this.securityInterceptor = securityInterceptor;
}
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(securityInterceptor).addPathPatterns("/**").excludePathPatterns("/login", "/logout");
}
}